Method of precooling the lading of refrigerator cars comprising the reversal of air flow



F. J. REILLY 2,439,487 ING THE LADING OF REFRIGERATOR METHOD OF PRECOOL CARS COMPRISING THE REVERSAL AIR FLOW Filed March 16, 1945 2 Sheets-Sheet 1 April 13, 1948.

INVENTOR.

wmazww Apnl 13, 1948. E J, REILLY 2,439,481 METHOD OF'PRECOOLING THE LADING OF REFRIGERATOR CARS COMPRISING THE HEVERSAL AIR FLOW Fil 2 Sheets-Sheet 2 ed larch 16, 1945 Patented Apr. 13, 1948 METHOD OF PRECOOLINGv THE LADING F REFRIGERATOR CARS COMPRISING THE REVERSAL OF AIR FLOW Frank J. Reilly, Daytona Beach, Fla., assignor of one-third to Clarence J. Loi'tus, Chicago, Ill.

Application March 16, 1945, Serial No. 583,097

2 Claims. 1

The present invention relates to an air conditioning system, and more particularly to an air conditioning system adapted for conditioning of commodities in a chamber.

Heretoiore it has been recognized that it is desirable to condition commodities loaded in a chamber such as a freight car or a chamber in a ship. It has been recognized that pre-cooling of. such commodities, particularly fruits and vegetables which are to reach the consumer in fresh condition is highly beneficial. Such Dre-cooling reduces the amount of cooling required during shipment of the commodity, by lowering the pulp temperatures. i Such lowering of pulp temperatures prevents deterioration of the fruit or commodity thereby producing a saving in shipment.

At present pre-cooling is used quite extensively. and the typical procedure involves loading afreight car and the connecting to the door of the freight car by means of a false door an air conditioning unit. Air is introduced at one level of the car and removed at the other. At the present time the maximum height of lading in the car body has been increased twenty-five per cent thereby increasing the time required for pre-cooling. Such increased lading also shows that an appreciable temperature difference occurs between the commodity adjacent the incoming air with respect to the commodity adjacent the outgoing air.

Thus for example, where the pre-cooled'air is introduced and passed through the load in one direction, part of the load may be nearly twenty degrees cooler than the balance. After a period of time, the temperatures will equalize, but the equalization of the temperature may be higher part thereof, for with my invention the contents.

are so pre-cooled by introducing and passing through the contents of the car a forced stream of pre-cooled air continuously but intermittently in opposite directions during the initial pre-cooling period.

My invention materially reduces the amount of time required for initial pre-cooling, since the reversal of air changes the air pattern of the distribution of air through the car. Thus the effective surface of the load to be cooled is increased. An increase in the efficiency of operation is obtained since the rate of cooling is maintained relatively high.

It is an object of my invention to provide a pre-cooling method and system whereby the contents of a refrigerator car or the like may be rapidly pre-cooled uniformly throughout to a predetermined temperature without overcooling or undercooling any appreciable part of the load or contents of the car.

Another object of the present invention is to provide an air conditioning system wherein the 245 direction ofthe flow of the air is periodically than is desired for the best condition of transportation of the commodity. If the air conditioning operation is stopped too soon, part of the load at least will be at an excessively high temperature, thus resulting in a deterioration in .the freshness or quality of theproduce by the reversed. r

Still another object of the present invention is to provide an improved pre-cooling system wherein the eifective surfaces exposed to the air conditioning medium are increased by periodically reversing the direction of the flow of the air medium; I Still another object of the present invention is to provide an air conditioning system which will maintain the maximum temperature difierence betweenthe incoming air and the produce to be sealed in a chamber.

A still further object of the present invention is to provide in an air conditioning system an arrangement for the reversal of the direction of air flow without changing the impeller ian.

Still another object of the present invention is to provide an improved air conditioning system 'which will be suitable for achieving diiferent I Figure 1;

Figure 3 is a detailed view of mechanism shown in Figures 1 and 2;

Figure 4 is an enlarged view of the apparatus seen in Figure 2 in the direction of the arrows along the line 44; and

Figure is similar to Figure 4 showing the apparatus in a different operating condition.

Referring more particularly to Figure 1 there is shown a refrigerator car l| having therein a through lading load |2 of perishable produce which is to be pre-cooled prior to shipment. ,As will be seen from both Figures 1 and 2', the lading preferably consists of crates or other similar containers which are placed in rows such that vertical air spaces are left between the several rQWs of containers. One door l3 of the refrigerator car is opened so that a plurality of flexible ducts l4 and I5 may be associated therewith. The ducts I4 and to are connected to an 'air conditioning apparatus housed in a cabinet l6 which a portion of the may be mounted so as to be readily movable. By

referring to Figures 2 and 4 it will be seen that the housing or cabinet l6 contains a motor l1 connected by a belt l8 to an impeller fan IS. The fan lil as shown in Figure 4 supplies air to the duct l5. Interposed between the duct l5 and the fan l9 are a plurality of cooling or refrigerating pipes 2| which may have associated therewith on either side dehydrating apparatus 22. Similar apparatus is interposed between the duct l4 and the outlet located just above the housing-of the fan l9. Thus air conditioning refrigerating or cooling pipes are provided together withthe dehydrating apparatus 24. The outer ends of the ducts l4 and I5 are connected to a false door having a lower opening 26 and an upper opening 21. The fan I!) is housed within a chamber 28 so that the fan l9 circulates and recirculates the air through the housing 28, the ducts H and I5, and the interior of a refrigerator car II.

In order t the cooling'pipes 2| and 23 may cool the air y absorbing heat therefrom, the cabinet 16 isprovided with a compressor or compressors such as the compressors 29 and 3| which may be driven from a suitable motor 32. The compressors Share connected to a suitable condenser 32 mounted within a chamber 33. The condenser may con itute any suitable apparatus or configuration of p pes which is to be air cooled. .In order to facilitate the cooling of the condenser 32, the chamber 33 is provided with a plurality of water cooling jets 34 which together with the air passing through the chamber 33 dissipate the heat in the condenser tubes. The chamber 33 is provided with an air inlet 35 from which air passes upwardly past the spray jets 34 and through the coils of the condenser 32 whereupon the air is forced outwardly from the chamber by a fan 36 driven by a suitable motor 31. The apparatus utilized for supplying a cooling medium to the air conditioning pipes 2| and 23 may be of any suitable type since the details of such an arrangement do not constitute a part of the present invention.

As may be seen from Figures 1, 2, and 3 there is mounted exteriorly of the cabinet IS a crank 38 connected to a ratchet wheel 39 arranged for cooperation with a pawl 4|. The ratchet wheel 39 is keyed to a sprocket wheel 42 which e gages the endless chain or belt 43 connected to "drive a sprocket wheel 44. The sprocket wheel 44 is connected to suitable means for orienting the hous- 4' ing IQ of the blower fan. From Figure 2 it will be seen that while only one fan has been mentioned actually two or more fans I9 may be used.

and both housings for these fans are connected together so that the outlet may selectively be arranged for operation either into the lower duct I5 or the, upper duct I4. In Figure 4 the fan I3 is directing the air outwardly throi'gh the duct l5 whereas in Figure 5 the fan I 9 is directing the airoutwardly to the upper duct I4.

In accordance with the present invention 1; is intended to supply an air conditioning fluid medium such as air, gas, or the like tothe ladlng so that the cool air moves in one direction toward the lading for a predetermined time and thereafter the direction of the air is reversed so that the cool air moves in the opposite direction toward the lading. It is immaterial whether the cycle of operation starts from the top or the bot tomof the lading.

This operation may be repeated until the loadcools down evenly and rapidly. To illustrate this" reversal in the direction of the flow of the air conditioning medium, the manually operable crank 38 has been shownfor moving the outlet of the fan I9 to either of the positions shown in Figure 4 or Figure 5, since other reversing means may be employed. It is within the scope of the present invention to provide automatically operable means for producing this reversal of the flow of 'air either in accordance with a predetermined time cycle or in response to temperature differences between the air and the produce.

Such operation may be obtained by the proper location of thermostats'positioned within the refrigerator car ll.

Proper precooling of a load requires the lowering of all pulp temperatures in a car of lading to approximately 40 F. The temperature mentioned has been accepted as the most desirable temperature for commercial usage since the insulation values of standard refrigerator cars do not permit lower temperatures. It a reversal of the flow of the circulating air is not provided, a typical operation-might be as follows. Assuming that the produce or fruit is loaded in the car at a temperature of 85 F., and air entering the car from an air conditioning uit is at 30 F. at the end of six hours" operation, the cooler portion of the load may be at 45 F. whereas the hotter portion of the load may be as much as twenty degrees higher. If only fifteen degrees diflerence is found between the hotter and cooler portions of the load, it will be found that after three hours after the termination of cooling, the average temperature will be about In order to avoid this rise of temperature, periodic reversal of the flow of air is provided so that in the arrangement such as shown in the drawing both the top and bottom of the load may be reduced to the lower temperature mentioned.-

Preferably in the practice of the invention, the car is so loadedthat by means of a grating or other suitable support 45 a passageway is, formed from the lower duct l5 to the opposite side of the refrigerator car II. This structure forms a plenum in the lower part of the load between such structure and the bottom of the car at and adjacent the car door opening to provide an air chamber and permit a through lading load; that is, the car is loaded from end to end abovethe structure 45 and through the car except for the air chamber below which will produce a pressure on the longitudinal spaces between the crates or containers from the center of the car to the bunker walls. Such an arrangement obviates the necessity of any bafile on the top of the load to prevent short circuiting of the air entering the car doorway in either cycle of circulation, and the air will contact the extreme top and bottom containers in the load.

Another advantage obtained from the reversal of the flow of the cooling medium through the refrigerator car is that the pattern of the air distribution is changed so that those portions of the load which might .not be contacted by as great an air fiow in one direction will be con tacted to a greater degree when the air flow is in the opposite direction. Thus the total surface presented to the cooling air is increased. Furmentioned, the apparatus and the system employed thereby may be used for the achievement of different classes of pro-cooling, refrigeration, heating, dehydrating, ventilation, gasing, and other services desired by the shipper.

For example where produce such as potatoes are loaded in a car, the apparatus may be used for even dehydration or drying of the potatoes which frequently are loaded in the car with moisture still adhering to the individual potatoes due to the washing of the potatoes prior to loading. By removing the excess moisture, the potatoes will arrive at their destination in a better condition. In the instance of certain other fruits, it has been desirable to sterilizethe lading by the introduction of certain disinfectant gases which will prevent spoilage of the load due to the formation of fungus, mold, and the like.

From the foregoing it is apparent that it is possible to perform the pro-coolin work within the limitation of railroad schedules since produce is loaded and sold for specific delivery dates based on such schedules. Since in cooling the products in a room or car with a cooling unit operating to discharge the air in only one direction, it would be desirable to turn or rearrange the packages to be cooled in order to expose surfaces and reduce the cooling time, the same results may be obtained in accordance with the present invention by merely reversing the direction of the air flow.

While for the purpose of illustrating and describing the present invention, a certain embodiment has been schematically shown and a. panticular application has been described, it is to be umlerstood that the invention is not to be limited thereby, since such variations and applications are contemplated as may be commensurate with the spirit and scope of the invention set forth in the following claims.

The invention is hereby claimed as follows:

1. A method on precoollng a load within the usual side-door refrigerator car having side doors midway the ends thereof to a predeterminedand substantially uniform temperature throughout the load during the initial precooling period without over-cooling any appreciable part of the load,

comprising through lading loading of the car with crates of perishable products and arranging said crates substantially the entire length of the car in the upper part thereof so as to provide for a relatively shallow air chamber as compared with the depth of the load extending across the car in the lower part of the load near the floor adjacent to the door opening, said chamber being further arranged in a substantial line with said side door. openings, and arranging said crates to provide a multiplicity of vertical air passages in open communication with said air chamber extending throughout the load and around the crates, cooling the air at substantially less than that of the perishable load by forcibly and rapidly driving streams of air so cooled through the side door into said chamber, thence through the multiplicity of air passages formed in the load and forcibly drawingthc air out of the car, and intermittently reversing during the precooling operation the direction (if travel of the streams of precooled air through the load and the multiplicity of air passages whereby the pattern of the precooled air distribution is intermittently changed, so that those portions of the load not being effectively contacted in one direction will be contacted to a greater degree upon the reversal of the air current. a

2. A method of providing and pre cooling through lading loads in the usual transportation cars having side doors midway the ends thereof which comprises the steps of loading the car from end to end with crates of perishable products and arranging and supporting such crates substantially across the entire length of the car in the upper part thereof so as to provide for a relatively shallow air chamber as compared to the depth of the load extending across the car in the lower part of the load near the floor adjacent to the door opening said chamber being further arranged in a substantial line with said side door openings, and arranging said crates to pro vide a multiplicity of vertical air passages in open communication with said chamber extending throughout the load and around the crates so as to permit streams of air to pass in eitherdirection through the load and providing a structure in the load at the top of said air chamber to support a through load above said space and forcibly passing streams of precooled air from'the ccn-.

ter of the refrigerator car into, through and out the load and refrigerator car intermittently in opposite directions during the pre-cooling period, for initially uniformly pre-cooling the load throughout.

FRANK J, REILLY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

